#include <iostream>
#include <cmath>
const double PI = 3.14159;
const double DENSITY = 7.8;
class Ball {
public:
    double radius;
    double surfaceArea() {
        return 4 * PI * radius * radius;
    }
    double volume() {
        return 4.0 / 3 * PI * radius * radius * radius;
    }
    double mass() {
        return volume() * DENSITY;
    }
};
int main() {
    Ball ball;
    std::cout << "Please input the radius of the ball: ";
    std::cin >> ball.radius;
    std::cout << "球的表面积是: " << ball.surfaceArea() << std::endl;
    std::cout << "球的体积是: " << ball.volume() << std::endl;
    std::cout << "球的质量是: " << ball.mass() << std::endl;
    return 0;
}